WO 2005/124063 describes a shelter that includes a ground sheet and a cover; the space between the ground sheet and the cover can be inflated by pumping air into the space to raise the cover and form the shelter. The cover is made of a fabric that has been impregnated with cement; the fabric may be a type of felt known as “wadding”, which is a loose non-woven fabric. Immediately before the interior space is inflated, the cover is wetted with water, so that, after inflation, the cement in the cover sets and forms a rigid shell that acts as a self-supporting roof for the shelter, which is particularly useful in providing temporary accommodation in emergency areas.
Spacer fabric is a known material and comprises a top face layer, a bottom face layer and pile yarns extending between the two faces. It is commercially available, for example from Culzean fabrics of Kilmarnock, United Kingdom; Scott and Fyfe of Tayport, Fife, United Kingdom and W Bull and Son Ltd (Baltex) of Ilkestone, United Kingdom. It is used to manufacture garments and other articles where the fabric must be thick but light and/or where the fabric should include an air gap, for example in cycle helmets, boot soles, fireman's clothing, body armour; mattresses and bandages; climate-control seating in vehicles. The pile yarns are self-supporting to space the two faces apart by a desired distance and to resist crushing forces, i.e. forces acting perpendicular to the plane of the faces. The thickness of the spacer fabric is determined during manufacture by choosing an appropriate length for the pile yarn. The yarns used for forming the two faces can be the same or different from each other and from the pile yarns so that it is possible to choose the properties of the two face layers and of the pile to provide the desired properties. Among the fibres employed are polyethylene, polyester, Nomex, Kevlar, polyamide and microfibre (Nomex and Kevlar are trademarks).
JP-A-04327272 discloses a woven or knitted lattice-like fibre sheet to which is applied a composition containing all the components of a thermosetting resin, and containing a large proportion of plasticizer. The resin composition is cured to provide a sheet having high flexibility, high strength, low elongation and good shape stability. Because of the high amount of plasticizer in the resin, the resin is flexible and so allows the sheet to be wound up on a roll.
U.S. Pat. No. 5,461,885 describes a hardenable substrate that is used for forming casts and splints for immobilising patients' limbs and joints that have been fractured, broken or strained. The substrate is formed of a fabric having two spaced-apart webs; a hardenable liquid composition is drawn into the space between the webs by capillary action and allowed to set. The liquid composition may be a resin or a liquid dispersion of plaster of Paris. The hardenable liquid sets in situ shortly after it has been added to the fabric.
US 2003/0077965 discloses the use of a spacer fabric in a resin infusion process or a resin transfer moulding process in which liquid resin is introduced into the fabric and allowed to cure/harden.